Method for making and processing soap



Feb.13, 1940. HTHURMN 2,190,615

METHOD FOR MAKING AND PROCESSING- SOAP Original Fileddan. 5, 1937 2Sheets-Sheet 1 Feb. 13, 1940.

B. H. THURMAN METHOD FOR MAKING AND PROCESSING SOAP 2 sneets-shee 2Original Filed Jan. 5, 1937 THIHHIHwHhHhHHMHIM e INVENTORG M/NH. URMANdrToR/vm'.

o a w 6 6 m n V xgllill Patented Feb. 13,1940

, 2,190,615 METHOD FOR AND PROCESSING Benjamin H. Thurman, Bronxville,N; Y., assignor'to Refining, Ina, Reno, Nev a commation of NevadaApplication January 5, 1937, Serial No. 119,168 Renewed October 3, 1939llclalms.

(c1. gen-41a) One feature of the invention is the production, bypresence of material amounts of glycerine,

of a friable soap as an intermediate or final product and which has newcharacteristics differentiating it from soaps now known. In producingthis friable product substantially anhydrous soap is cooled from molten,plastic, or semiplastic condition, preferably while out of contact ,withthe atmosphere or oxidizing agents, to form a solidified soap havingincipient planes of fracture throughout. Upon extrusion this soap breaksup almost entirely into a powder or into small masses which are easilycrushed into a fine powder. This friable soap has unexpected propertiesin that item be directly and uniformly hydrated by adding water thereto.

It will uniformly absorb water in considerable amount as distinct fromordinary drastically dried 'soap powders which will form a gel when suchan amount of water is added and thus can- 'not be uniformly hydratedwhen water is added thereto. This friable soap, as well as a novelmethod and apparatus for producing same, is a part of'the presentinvention. 1

In the preferred mode-of operation the soap is produced continuouslyItmay be dellvered from the apparatusin powder or fiake form and havingthe desired moisture content, or it may be continuously produced in theform of bars or cakes. In this connection the friable soap may beproduced as an intermediate product, if desired, by cooling thesoap frommolten, plastic,

or semi-plastic condition while it is substantially anhydrous, waterbeing later added in controlled amount. This mode 'of operation is apartof 5 the present-invention, as well as the production of friable soap asan end product.

In forming the friable soap any suitable method can be used for formingamass of soap which is in molten, plastic or semi-plastic condition. Thesoap should be substantially anhydrous,

containing at most not more thana very few per cent of water. It isbrought into this condition by application of heat, and extremefluidity'immediately preceding cooling is not requisite.

5 The soap should be kept from theatmosphere while at the hightemperatures necessary, thus preventing oxidization, discoloring, andother deleterious reactions. If the soap-making materials used areofsuch character as to form 50,.glycerine, this glycerine canbe'advantageously removed in'whole or in part before cooling the mass,and a mass of molten, plastic, or semiplastic soap will usually containno great proportion of glycerlne. Howeven'the friable nature of theproduct is apparently not destroyed if, this is desired in the finishedsoap.

The next step is to cool this soap from its molten, plastic, orsemi-plastic condition in such manner that incipient planes of fractureextend 5 throughout the cooled mass, making it extremely friable. Thiscooling can best be accomplished during continuous movement of the soap,and it is important that the moisture content of the soap should not begreatly increased prior to 10 coohng, otherwise the friable nature ofthe soap be destroyed.

The resulting product will break up largely into soap powder if thestream of friable soap is extruded, and any remaining masses can be 15readily broken up by application of small crush-. ing pressure.

The resulting powder, or the masses of friable soap' not I yetdisintegrated into a powder, have the unexpected property of directlyand uni- 20 formly absorbing moisture even though it is a drasticallydried product. A desired amount of water may be added to a mass of thesoap and I gentle mi ging will cause uniform hydration of the soap. U Onthe other hand, the water may 25 be supplied to the soap continuously asfast as produced, it a continuous process is utilized.

However, the method and apparatus is not limited to the production ofthis friable soap as an intermediate or final product and many 30features are new regardless of this ,use. For instance, the system forremoving the soap from the vacuum chamber and subsequently processingthe soap is new, -as ,-is also the cooling system which permitsattenuation of the soap to 5 facilitate removal of heat therefrom. Soalso,

the method of introducing the reaction products into the vacuum chamberis new, and the complete system'permits hydration and addition ofbuilders or other material during continuous 40 movement of the soap.

Other new features forming a'part ofthe invention will be evident fromthe followin d scription.

One convenient and very satisfactory ap paratus for making andprocessing soap of this friable or non-friable character is disclosed inthe attached drawings, in which:

Fig. 1 shows the complete apparatus, partially in-section.

Fig, 2 is a section of the conveyor system taken on the line 2-2 of Fig.1.

Fig. 3 is a sectional view of one form of valve, being takenas indicatedby the lines j H of E18. 2. 55

Fig. 4 is a view of one type of member extending into the conveyor forbreaking up the soap stream, being taken as indicated by the line 4-4 ofFig. 2.

Fig. 5 is taken as indicated by the line 5-4 of Fig. 2 and shows one ofthe cooling grids.

Fig. 6 is a sectional view taken on the line H oi Fig. 1.

The materials used in the process include a saponiflable material whichmay be any material capable of being saponified to form soap,

for instance, various fats, glyceride-type oils, greases, etc. Thesaponifying material may be any material which will act with thesaponiiiable material to form reaction products including soap and avaporizable material, such, for instance, as glycerine or water, orboth. Examples such saponifying materials are aqueous alkaline solutionsof caustic soda, caustic potash, etc. In using he apparatus disclosed,these materials are respectively contained in tanks HI and II and may betherein heated to increase the fluidity or facilitate satisfactorymixing.

Proportioned quantities of these materials are mixed in any suitableway. In the continuous system shown, proportioned streams are with drawnby pumps i2 and i3 and delivered to a mixer i4 through closed conduits.The pumps may be inter-connected by a variable-speed means I80 tocontrol the proportions. The mixer i 4 may be of any suitable type andmechanical mixers can be used, though a satisfactory mixture can beobtained by injecting one material into a stream oi the other as itflows through a chamber of the mixer I4. In the continuous system shownthe pumps develop suflicient pressure to force the mixture through theheating zone.

This mixture moves through a pipe I5 to any suitable type of heater IS,the pipe I! being equipped with suitable devices i1 and il to indicatethe pressure and temperature of the mixture. Various types of heaterscan be used which provide a heating zone through which the mixturecontinuously flows. The type illustrated is particularly suited to acontinuous process and includes a coil of pipe I! heated by a burner 20or by any other heating means. A suitable thermostat may be used tocontrol the amount of heat applied.

In the heating zone defined by the coil I! complete saponiflcation takesplace under heat and pressure and the reaction products dischargingthrough a pipe 22 comprise a mixture of soap," water, and glycerine'inthe event that an aqueous alkaline solution was used as the saponifyingmaterial. In this pipe the water will be in the form of steam, and theglycerine will be either in liquid or vapor state in wholeor in part.The pipe 22 is equipped with a pressure gauge 23 and a thermometer 24.

These reaction products are continuously discharged into a separatingchamber II through a valve 28 and a nozzle 21 which may be used to Ithrottle the flow if desired. However, in some instances no throttlingaction at this .point is necessary. The nozzle 21 is preferably sodirected that the soap in the reaction products impinges against thewalls of the chamber II and moves downward therealong as a thin stream.This nozzle may be tangentially directed if desired, in which event thesoap may move downward in a curved path.

In the chamber II vapors of water or glycerineorbothseparateiromtheaoapandmovethrough smaller than the conveyorhousing 49 so as a pipe 20 to a condenser system if it is desired tocondense these vapors. If both water and glycerine vapors are present,it is possible to fractionally condense same by use of a glycerinecondenser 3| and a water condenser 3 I. The condensed glycerine movesdownward throughabarometric column 32 with its lower end submerged inglycerine in a tank 33, this barometric column being of sumcient heightto balance the low pressure maintained in the chamber 25. The watervapors are condensed in the condenser SI and move through a barometriccolumn 34 to a tank it A vacuum pump 3' is connected to the condenser IIand maintains a low pressure in the chamber II by forcibly withdrawingthe vapors therefrom.

or hot inert gas introduced into the chamber.

25 exerts its own partial pressure and facilitates removal of glycerinevapors from the soap if it is desired that the glycerine content of thefinished soap be low. Sufficient heat is applied, either in the heaterii or in the chamber 25, or both, to insure that the soap reaches thebottom of the chamber 25 in molten, plastic, or semi-plastic condition.

A rotating scraper 45, suitably driven, moves the soap from the bottomwall of the chamber 25 into two troughs 41 extending transversely acrossthis chamber and forming a part of the conveyor system. Each of thesetroughs can be heated or cooled as desired by circulation throughjackets 48 extending therearound.

Extending as a continuation of each trough is a conveyor housing 4! ofcylindrical shape, and a suitably driven soap-advancing screw It ispofltioned in each housing and extends into the corresponding trough 41.Each screw provides a shaft 5| driven by a gear 52, and provides ahelical vane 53 of a diameter only very slightly to continuously forcethe soap into a chamber 55. I! desired, each screw 10 may be formed inflights, separated by spaces receiving members 50 which extend into theconveyor housing. To make each of the members 58 removable andadjustable, it may extend through a nipple 5B, being-carried by a cap 59threaded to the nipple as shown in Fig. 4. break up the soap stream, andserve to mill or plod the soap during advancement. This constructionthus provides conveyors B0 and SI for continuously removing the soapfrom the chamber II. In some instances a single conveyor is suiilcient.

.Each conveyor is preferably provided with a pipe '2 whichreturns to thechamber 25 any vapors which may separate from the soap while in theconveyor.

It is desirable to,cool the soap while in the conveyors Cl and I. Acooling medium may be circulated through a .jacket 63 surrounding eachconveyor housing 4!. In addition, it is often desirable-to internallycool the annular stream or soap moving in each conveyor. Inthis-capecity, the shaft ll of each conveyor is hollow and a pipe 04extends therein. vA cooling medium,

These members serveto such as water, may be forced into the pipe 84 anddischarged into a space 05 surrounding a sleeve 08, this water returningthrough the annular space GI-around the pipe 84 inside the shaft 5|,being ultimately discharged through a head 88.

It is often desirable to make that end of the shaft 5| next the chamber55 of larger diameter, to provide an enlargement or head 68. Thisdecreases the available space for the soap and acts to compress same. Inaddition, it causes attenuation of the soap, thus facilitating coolingthereof.

The heat conductivity of the soap in such a soap stream is quite low andin many instances it is desirable to further cool the soap by movingthis soap stream through one or more cooling grids: I and 7| which mayextend through the chamber 55. Each of these cooling grids is formed ofa plurality of pipes positioned close to each other so that the soapmust move through the rather small spaces therebetween. Water or othercooling medium is circulated through these pipes,'for instance, byconnecting these pipes to headers 13 such as shown in Fig. 5. By thusfurther attenuating the soap very eflicient cooling can be obtained.

The two soap streams discharged from the conveyors 60 and SI move intoan intersecting conveyor 80, the chambers 55 opening on a passage formedin a conveyor housing 8I in which a screw 82 rotates. This screw isformed similarly to the screw 50, providing an enlarged head 83 andbeing hollow so that water or other cooling liquid can be circulatedtherethrough Whenintroduced into a pipe 84, this water being dischargedthrough a pipe 85. The screw 82 is similarly formed in flights betweenwhich members corre-' sponding to the members 58 extend. The soap isthus milled and plodded during passage through the conveyor 80 and isfurther compressed by the enlarged head 83 before discharge into achamber 86. The conveyor housing 8| is jacketed as indicated by thenumeral 81 and a cooling medium is circulated through this jacket tofurther cool the soap. The screw 82 is turnedas by a gear 88 preferablyat a faster rate than the screws 50, especially as it is desirable tomake the conveyor housing 8| somewhat smaller indiameter than theconveyor housings 48. In addition, the heli-' cal vane forming a part ofthe screw 82 is preferably of smaller pitch near the conveyor 80 thanthroughout the remainder of its length, this smaller pitched portionbeing indicated by the numeral 89.

If desired, the soap may be delivered from the chamber into theatmosphere, being extruded through a valve 90, the subsequent portion ofthe equipment illustrated being disconnected.- This mode of operationcan be utilized if the soap has been cooled to such an extent thatexposure to the atmosphere will not result in deleterious .reactions,such as discoloring or spontaneous combustion. Depending upon operatingconditions in the preceding\part of the'system, the soap thus pivoted atand adjusted by an arm 83 so as to extend partiallyacross the chamber".This valve acts in part as a vacuum seal, being preferably adjusted sothat the available opening through which the soap dischargesiscompletely filled by the soap stream. Thus, even ii. the chamber 25 isunder a high vacuum, no air will move rearward through the conveyors toimpair the vacuum in this chamber. In this connection, the soap streamin the conveyor 80 acts as a vac uum seal, and if the chamber 25 ismaintained under high vacuum, pressure on the soap will progressivelyincrease during flow through the conveyor system described.

In many instances it is preferable to continu the processing of the soapbeyond the valve 90 for purposes of hydration, addition of builders orfillers, etc. Thus, the soap moving through the valve 80 may movedirectly into a conveyor I00, or may drop thereinto through a memberIOI. This conveyor provides a screw I02 which may be rather loosefitting and which is rotated to further plod and advance the soap. Ifdesired, various builders or fillers may be introduced into the soap atthis time, for instance, by moving same under pressure through a pipeI03. Such material may bemoved along the pipe I03 and into the soap byuse of a screw rotating in this pipe. Materials thus introduced into theconveyor I00 will be intimately mixed with the soap therein. Theconveyor I00 builds up sufiicient pressure to extrude the soap throughone or more orifices, preferably through a perforated plate I 04, into ahousing I05.

The soap emerges from the openings of the perforated plate and drops asa powder or in small masses into a throat formed between rotating rollsI01 and I08 where any masses of soap are crushed and where the soap isfurther attenuated and compressed into a thin layer. These rolls arehollow to provide chambers I09 and a cooling medium is circulatedthrough these chambers.

"This is an excellent way of further cooling the prolonged contact withthe atmosphere.

It is often possible to use the rolls I 01 and I08 for hydrating thesoap, especially if 'the soap is of such a nature that water can bedirectly added thereto to be uniformly absorbed thereby. In thisconnection, the entire-external length of the roll I01 may be wetted bywater sprayed thereon or supplied through an elongated nozzle II 2 toform a layer or film of water along this external surface. Any excesswater above .the desired quantity may be removed by a scraper II 3extending along this external surface and adjusta ble in, radialposition relative thereto. This scraper II3 may be mounted on one ormore screws I I4, and nuts I I5 may be used to vary the distance betweenthe wiping edge and the periphery of the roll I01 to form a film ofwater on the to further distribute the water uniformly.

The soap drops frombetween the rolls I01 and I08, or is scraped.therefrom by scrapers I I8, and

moves into a hopper I I8 which discharges into a throat formed by rollsI and I 2I which are also hollow so that a cooling medium can becirculated therethrough. If desired. further moisture can be applied atthis point.

The soap drops from between the rolls I and i2 I, or is scrapedtherefrom by scrapers I25, and reaches a belt conveyor I which extendsthrough a small opening of the housing I05 and conducts the soap to ahopper I28. The soap at this point may be in'powdered or flake form andif desired may be marketed as such. However, if it is desired to formthe soap into a bar the hopper I26 may discharge into an extrudingdevice which will compact the soap and extrude same through an orificeI28. A screw I29 rotating in a housing I30 may serve to compact the soapinto a homogeneous mass, supplying sufflcient pressure to extrude thesoap as a continuous stream through the orifice i28. This stream of soapmay be cut into bars as desired.

In general, it can be said that this system can be operated to producevarious diflerent forms and types of soap. Proper control of pressureand temperature conditions at various points in the system will largelycontrol'in this regard, and the condition of the soap in the bottom ofthechamber 25 is one important factor. Primarily, the temperature andpressure conditions in the coil [9 and in the chamber 25 control thecharacter of this soap which is withdrawn from the lower end of thechamber 25.

It will be clear that the pressure in the coil l9 decreasesprogressively from the inlet end to the exit end due primarily to pipefriction retarding the flow. For instance, when using the throttlingnozzle 21 the pressure in the pipe 22 may be in the neighborhood of 50lbs. per sq. in. or even considerably more if desired, while thepressure in the pipe i5 may be much higher, often as high as 350 to 450lbs. per sq. in. If no throttling action is desired the vacuum in thechamber 25 will carry back a considerable distance into the coil [9.Fromthe angle of temperature, it will be clear that this temperatureincreases progressively during flow through the coil l5.

These conditions of temperature and pressure in the coil is should be soregulated as to give complete saponification therein. In addition, allof the water, and all or at least a part of the glycerine, should bevaporized in the coil 19 if the friable soap product is to be produced.If the flow of reaction products is throttled, as by the nozzle 21 orthe valve 26, some or all of the remaining unvaporized glycerine willflash into vapor at the lower pressure existing in the chamber 25. Sucha vacuum condition in this chamber is very desirable in that it reducesthe boiling point of the glycerine and permits the soap to be withdrawnfrom the chamber in substantially glycerine-free condition if desired.The presence of steam in the chamber 25 will further lower the boilingpoint of the glycerine due to the law of partial pressures.

The friable nature of the soap results from cooling same from a molten,plastic, or semiplastic condition. Such. a condition can sometimes bebrought about by utilizing suflicient heat in thecoil l9 and withoutaddin additional heat in the chamber 25 but it has been very d s able toutilize a heating medium in the Jacket 40 especially when starting upthe apparatus and preferably throughout continuous operation thereof.Application oi. heat to this chamber will decrease the necessarytemperature in the coil 39 and will insure that the soap withdrawn fromthelowerendofthischamberwillbeln molten, plastic, or semi-plasticcondition.

It will thus be apparent that no definite range of temperatures andpressures in the coil I! can be named, for these will vary with thetemperature and pressure in the chamber 25 and also with the particularsaponiflable material utilized. Further, no definite temperatures can beset forth as necessary for maintaining the soap in molten, plastic, orsemi-plastic condition, for these temperatures will vary with differentsoaps. In general, however, it can be said that soaps made fromcottonseed oil should be at a temperature above about 455 F., and soapsmade from palm oil or tallow should usually be at a temperature above518 F. if such soaps are to be in molten condition. Somewhat lowertemperatures are permissible if the soap is to be in plastic orsemiplastic condition.

'The temperature of the reaction products in the pipe 22 may be abovethese values, for some cooling of the soap takes place in the chamber 25unless a large amount of heat is added at this time. Some cooling is notdetrimental, for it has been found that the soap when once molten can becooled somewhat without changing it from molten, plastic, orsemi-plastic condition. In fact, molten soap can be reduced to atemperature somewhat below that necessary to bring it into moltencondition and yet be quite fluid. If no large amount of heat is added inthe chamber 25, best operating temperatures in the pipe 22 will often beabove 500 F. if the soap is to be in molten, plastic, or semi-plasticcondition in the bottom of this chamber. With many saponifiablematerials, best results have been obtained when temperatures in the pipe22 were as high as 570 F. or even higher, when no large amount of heatwas added to the chamber 25.

The preferred mode of operation is to use coil temperatures sumcientlyhigh that the soap reaching the side walls of the chamber 25 will bequite fluid so as to readily move downward there along. This facilitatesseparation of vapors from the soap due to the fact that this soap movesdownward as a relatively thin layer, thus exposing a large surface tothe low-pressure in the chamber 25. This feature of flowing the soapalong the walls of the chamber 25 also prolongs the time necessary forthe soap to reach the bottom of this chamber and thus gives additionaltime for vapors to separate. The tendency for this downward-flowing soapto somewhat cool can be attributed to loss of heat by radiation, or tovaporization of glycerine during this downward movement. However, evenif no large amount of heat is added to the chamber 25, this coolingusually does not exceed F., and can be made much smaller or eveneliminated, if sufflcient heat is added to this chamber. Application ofsumcient heat to the chamber 25'may even slightly increase thetemperature of the soap.

"The controlling factor is that the soap in the 2 cooling is preferable.with the system shown 7 it is possible tov cool the soap in a shorttime, usually between four and twenty minutes, depending upon the lengthof the conveyors and the amount of soap moving through the system. Whileslower cooling can sometimes be used, it has been found that rapidcooling is preferable in that it assists in forming the incipient planesof fracture throughout the soap which results in its friable nature.Attenuation of the soap prior to or during cooling will greatlyfacilitate rapid cooling, and the internal and external cooling of thesoap streams in the conveyors, in conjunction with the cooling grids 10and II will be found very effective for this purpose. In addition,cooling on rolls is even more effective in this regard.

By way of example, the system can be used to produce the friable anddirectly hydratable soap mentioned above by operating under thefollowing temperatures and pressures given. With a, saponifiablematerial comprising 70% tallow and 30% cocoanut oil, and with a solutionof 31 B. caustic solution as a saponifying material, pressures in thepipe I5 have been used between 350 and 450 lbs. per sq. in. with a coilI9 composed of pipe .of A" internal diameter and about 550 ft. long.These pressures will be different with coils of different length andinternal diameter. The pressure. in the pipe 22 may be about 50 lbs. persq. in. though this is not critical, and the temperature therein in thisexample may be from 560 to 570 F. The reaction products will bedischarged through the nozzle 21 against the walls of the chamber 25,the soap under these conditions being sufficiently molten to run downthese walls. Due to expansion and radiation losses, the temperature ofthe soap in the bottom of the chamber 25 will be in the neighborhood of500 F. or somewhat higher, the temperature in the Jacket 40 being about536 F. A vacuum of 27-28 inches of mercury in the chamber 25 will permitremoval of substantially all of the glycerine in this example. This soapis cooled in the conveyors 60, 'BI and to produce a friable soap.

Very satisfactory results can be obtained by able water can be added tothis powder and by 7 any simple mixing operation it will be uniformlyabsorbed to produce a soap powder hydrated to the desired. extent. Theamount of hydration thus possible varies with different soaps, but

with most soaps 8 to 20% or more water can the soap while in theconveyors to such. an

extent that it canbe discharged into the atmosphere from the valve 90.By way of example, it can continue its movement by moving through theconveyor I00, being further cooled on the rolls I01 and I08, and vbeinghydratci at this point. The soap will drop in flake r powdered form fromthe rolls I01 and III! and can be used in this form, or it can be.urfi-er cooled on the rolls 20 and. i2l, and adCT'o al water can beadded at this point, if :1 Si d. The soap is then withdrawn by the beltconveyor I25 and is ready for use. If bar soap is desired, this productcan be moved through the-extrusion device I30, being extruded as a barthrough the orifice I28. This bar can be cut up to form cakes.

The hydratable character of this soap is not changed, by adding variousfillers or builders in the conveyor IIlII. Further, the presence of someglycerine does not ,in itself defeat this hydratable characteristic,though best results have been obtained when substantially all of theglycerine has been removed.

The system herein disclosed can be used to continuously make other typesof soap of a non-friable nature. For instance, if lower tern-*-peratures are used in the coil It, the soap can be collected in powderedor granular form in the chamber 25 and withdrawn by the conveyor systemshown. So also, if the absolute pressure in the chamber 25 is higherthis type of soap may be collected in the chamber 25 even with the coiltemperatures mentioned above. Such powdered or granular soap may stillcontain all or a portion of the glycerine if desired, and all or aportion of the water may be allowed to remain therein under properconditions of temperature and pressure in the system. As before, thistype of soap will be continuously with drawn by the conveyors 60, 6:3,and to, being cooled therein. If cooled to a sufficient degree, thissoap can be discharged into the atmosphere through the valve in the formof a temporarily adhering mass of soap particles. Alternatively, thesoap, can be delivered from the valve 90 to the conveyor I00, andfillers or builders may be there added. This soap may thus beconditioned in a continuous process so that when it is dischargedthrough the perforated plate I04, it is in condition for use.

If powdered or granular soap is withdrawn from the chamber 25, this soapmay be hydrated by adding moisture thereto during flow through theconveyor system. For instance, water or steam may be supplied throughpipe 200 into the conveyors 60 and 6 I or through a pipe 20I to theconveyor 80. Further, water may be introduced into the conveyor I00through a pipe 202 to hydrate the soap. Such a method of hydration bydirectly introducing the water into one or more of the conveyors is tobe avoided if the friable and uniformly hydratable soap is to beproduced. However, this method of hydration can be successfully usedwith other types of soap. If used, it is sometimes preferable tointroduce the water while the soap is still at such temperature that thewater will be vaporized, thus more uniformly distributing the water.

The hydrated soap resulting from this mode of operation may be used asdelivered from the perforated plate I04, or may be compressed into barsin an extruding device. extruded through the perforated plate I04 may becompressed between the rolls shown to form flakes which may be used inthis form or compressed into a bar if desired. In this instance the soapreaching the rolls will already be hydrated and So also,.the soap thusto the soap.

If.a powdered soap is to be collected in the chamber 25, one or morebaffles may be provided in the upper end so that the vapors move througha tortuous path. This will tend to separate any minute particles whichmight tend to be carried upward with the vapors. Such bailies areusually not necessary if the process is so operated as to producemolten, plastic, or semi-plastic soap in the chamber 25. Regardless ofwhether the soap is withdrawn from the chamber 25 in molten, plastic,semi-plastic or powdered condition, the conveyor system willcontinuously withdraw this soap without impairing any vacuum whichexists in thischamber, for the soap and the valve 80 will act to sealthis chamber from the atmosphere.

The system disclosed has wide utility in making various types of soapfrom various'ingredients,

and the present invention has novelty in the process, the apparatus, andthe friable soap product produced.

I'he term friable as employed in the product claim hereof is intended todefine a soap product which can be reduced to a powder by such slightpressure as is produced by rubbing a portion of said soap between thethumb and iinser.

I claim as my invention:

1. A method of making soap, which includes the steps of: forming a massof substantially anhydrous soap in a molten, plastic, or semi-plasticcondition; removing a stream of said soap from said mass, cooling saidstream of said soap while in substantially anhydrous condition and whilein a space confined from the atmosphere to form a friable soap which isdirectly and substantially uniformly hydratable by adding moisturethereto; continuously breaking up said friable soap as fast as produced;and adding moisture to the brokenup soap in controlled amount to hydratesame.

2. A method of making soap, which includes the steps of: forming a massof substantially anhydrous soap in a molten, plastic, or semi-plasticcondition; and forming a friable soap therefrom which will substantiallyuniformly absorb water by removing a stream of said soap from said mass,coolingsaid stream of said soap from its molten, plastic, orsemi-plastic condition while in said substantially anhydrous conditionin a space confined from the atmosphere and then further cooling saidsoap on cooling rolls.

3. A method of making soap which includes the steps of: forming a massof substantially anhydrous soap in a molten, plastic or semi-plasticcondition; removing a stream of said soap from said mass, and coolingsaid stream of soap while in substantially anhydrous condition and whilein a space confined from the atmosphere to form a friable soap which isdirectly and substantially uniformly hydratable by adding moisturethereto and continuously moving and attenuating said soap during'saidcooling.

4. A method of making soap which includes the steps of: forming a massof substantially anhydrous soap in a molten, plastic or semi-plasticcondition; removing a stream of said soap from said mass, and coolingsaid stream of soap while in substantially anhydrous oondition'and whilein 2,190,015 rolls need not serve this function of adding water a spaceconfined from the atmosphere to form a friable soap which is directlyand substantially uniformly hydratable by adding moisture thereto andmaintaining a vacuum during at least a portion of said cooling.

5. A method of making subdivided soap from a mass of substantiallyanhydrous soap in molten, plastic, or semi-plastic condition, whichmethod includes the steps of: withdrawing a stream of soap from saidmass; continuously cooling said soap moving in said stream while stillsubstantially anhydrous to form a friable mass capable of uniformlyabsorbing moisture when added thereto: reducing the resulting friablesoap to subdivided form; and adding moisture to the subdivided soap incontrolled amount to hydrate same.

6. A method as defined in claim 5 including the step of adding amaterial such as a soap builder or filler to the cooled soap streambefore said moisture is added.

7. A method of continuously making soap, which includes the steps of:continuously heating a mixture of a saponifiable material and asaponifying material to form reaction products including soap. andvapor; continuously introducing said reaction products into a separatingchamber maintained under vacuum; continuously removing vapor from saidchamber to leave therein substantially anhydrous soap in molten,plastic, or semi-plastic condition; continuously withdrawing a stream ofthis soap from said chamber and cooling same while still substantiallyanhydrous and from its molten, plastic, or semi-plastic condition toform a mass of friable soap which will directly and uniformly absorbwater; continuously subdividing the stream of soap; and hydrating thesubdivided soap.

8. A method of continuously making soap, which includes the steps of:continuously heating a mixture of a saponifiable material and asaponifying material to form reaction products including a soap andvapor; continuously introducing said reaction products into a separatingchamber maintained under vacuum by impinging said reaction productsagainst a wall of said chamber, the soap flowing down said wall andreaching the lower end of said chamber in substantially anhydrousmolten, plastic, or semiplastic condition; continuously removing vaporfrom said chamber; continuously moving a stream of the molten, plastic,or semi-plastic substantially anhydrous soap from said chamber in such amanner as not to impair the vacuum therein; and cooling this stream ofsoap before exposure to the atmosphere to form friable soap which willsubstantially uniformly absorb water.

9. A method as defined in claim 8 in which heat is applied to saidchamber.

10. A method as defined in claim 8 in which heat is applied to saidchamber by introducing a hot medium thereinto which is withdrawn with Isaid vapors.

